Take Heed When the Heat Is On

17th Jul 2015

Summer is a great time to be outside. That's true whether your summertime pleasure is lying on a sandy beach soaking up rays or knocking out a strenuous workout that could include swimming, biking or running, or even a combination of all three as you prep for that upcoming triathlon. If your idea of summertime fun is something in between, like a round of golf or a leisurely jog on the local greenway, then by all means go for it.

In doing so, however, stay alert and pay attention – to yourself and not just your surroundings, although that is important, too. This is the time of year you need to be eagle-eyed aware of the possible hazards of hot times in the city, and elsewhere. This isn't just about fending off mosquitoes or protecting your skin from the sun's damaging rays – those have been discussed in this space earlier – it's about employing measures to safeguard yourself from heat injury.

At an extreme, a heat injury can be a matter of life and death, although taking a few precautions can keep you safely distanced from danger. Drink plenty of fluids such as water or sports drinks with electrolytes such as Gatorade or Powerade (avoid caffeine and alcohol), schedule physical activity for the relative cool of early morning or early evening, use sunscreen (at least 15 SPF), and wear comfortable, loose clothing that allows your body to "breathe." Caution: don't even think about layering yourself up head to toe in jogging outfits or sweats as a weight-loss gimmick when it’s 95 degrees outside. That's begging for trouble.

Generally speaking, there are three incremental levels of heat injury: going from bad to worse, they are heat cramps, heat exhaustion and, in the real danger zone, heat stroke. Webmd.com identifies a fourth level between heat cramps and exhaustion – heat syncope, which involves fainting.

All levels involve prolonged exposure to heat and humidity without relief or adequate intake of fluids to replenish what's been lost through perspiration. If it's hot outside and you are sweating profusely, that's a good sign: it tells you that your body's cooling mechanisms are working properly; keep hydrating to keep your internal AC unit humming.

Heart injury doesn't practice age discrimination, although the risk is greater for children and adolescents for whom rest and hydration are alien concepts. Children who have chronic health problems, are overweight or are taking certain medications are more prone to heat-related illnesses, according to hopkinsmedicine.org. Also, heavy clothing such as band or football uniforms during sustained periods of exertions also are risky. Regards medication use: take time to discuss with your health care provider their use amid summer heat.

The key variable in all this is heat index, a combination of temperature and humidity. The magic number for heat index is 90: anything above that quickly ramps up the heat-injury danger. By itself, "a relative humidity of 60 percent or more hampers sweat evaporation, which hinders your body's ability to cool itself," says webmd.com.

Let's consider the symptoms. Heat cramps, the mildest of the three levels of heat injury, typically include agonizing muscle cramps and spasms during or after intense exercise. It gets progressively worse with heat exhaustion, in which the body loses water and salt through dehydration. Signs include excessive thirst, weakness, and headache, followed by nausea and vomiting, and dizziness. This means it's time to cease all activity, rest in a shaded, cool place – preferably air conditioning if it's nearby – and drinking cool water or sports drinks.

This brings us to heat stroke, the medical definition of which, according to webmd.com, is when the core body temperature surpasses 105 degrees F. Heat stroke indicators – the sufferer likely has already progressed through heat cramps and heat exhaustion – include warm and dry skin, no more sweating, breathing that is rapid and shallow, and rapid but weak pulse rate. It's time to call 911 and immediately get that person to a cool environment, wetting his or her skin with a sponge or garden hose, fanning them and applying ice packs to the armpits, groin, neck and back.